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  • 1
    Electronic Resource
    Electronic Resource
    Biogenesis and turnover of peroxisomes involved in the concurrent oxidation of methanol and methylamine in Hansenula polymorpha (1981)
    Springer
    Archives of microbiology 129 (1981), S. 35-41 
    Details
    ISSN: 1432-072X
    Keywords: Peroxisome ; Methanol ; Methylamine ; Yeast ; Hansenula polymorpha ; Alcohol oxidase ; Amino oxidase ; Catalase ; Catabolite inactivation ; Turnover ; Cytochemical localization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Growth of Hansenula polymorpha in shake flasks and chemostat cultures in the presence of methanol as the sole source of carbon and methylamine as the sole source of nitrogen was associated with the development of peroxisomes in the cells. The organelles were involved in the concurrent oxidation of these two compounds, since they contained both alcohol oxidase and amine oxidase, which are key enzymes in methanol and methylamine metabolism, respectively. In addition catalase was present. Peroxisomes with a completely crystalline substructure were observed in methanol-limited chemostat-grown cells. Amine oxidase probably formed an integral part of these crystalloids, whereas catalase was present in a freely diffusable form. Transfer of cells, grown in a methanol-limited chemostat in the presence of methylamine into glucose/ammonium sulphate media resulted in the loss of both alcohol oxidase and amine oxidase activity from the cells. This process was associated with degradation of the crystalline peroxisomes. However, when cells were transferred into glucose/methylamine media, amine oxidase activity only declined during 2 h after the transfer and thereafter increased again. This subsequent rise in amine oxidase activity was associated with the development of new peroxisomes in the cells in which degradation of the crystalline peroxisomes, originally present, continued. These newly formed organelles probably originated from peroxisomes which had not been affected by degradation. When in the methanollimited chemostat methylamine was replaced by ammonium sulphate, repression of the synthesis of amine oxidase was observed. However, inactivation of this enzyme or degradation of peroxisomes was not detected. The decrease of amine oxidase activity in the culture was accounted for by dilution of enzyme as a result of growth and washout.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00417176
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  • 2
    Electronic Resource
    Electronic Resource
    Arthrobacter P 1, a fast growing versatile methylotroph with amine oxidase as a key enzyme in the metabolism of methylated amines (1981)
    Springer
    Archives of microbiology 129 (1981), S. 72-80 
    Details
    ISSN: 1432-072X
    Keywords: Arthrobacter ; Facultative methylotroph ; Amine oxidase ; Catalase ; RuMP cycle of formaldehyde fixation ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A facultative methylotrophic bacterium was isolated from enrichment cultures containing methylamine as the sole carbon source. It was tentatively identified as an Arthrobacter species. Extracts of cells grown on methylamine or ethylamine contained high levels of amine oxidase (E.C. 1.4.3.) activity. Glucose- or choline-grown cells lacked this enzyme. Oxidation of primary amines by the enzyme resulted in the formation of H2O2; as a consequence high levels of catalase were present in methylamine-and ethylamine-grown cells. The significance of catalase in vivo was demonstrated by addition of 20 mM aminotriazole (a catalase inhibitor) to exponentially growing cells. This completely blocked growth on methylamine whereas growth on glucose was hardly affected. Cytochemical studies showed that methylamine-dependent H2O2 production mainly occurred on invaginations of the cytoplasmic membrane. Assimilation of formaldehyde which is generated during methylamine oxidation was by the FBP variant of the RuMP cycle of formaldehyde fixation. The absence of NAD-dependent formaldehyde and formate dehydrogenases indicated the operation of a non-linear oxidation sequence for formal-dehyde via hexulose phosphate synthase. Enzyme profiles of the organism grown on various substrates suggested that the synthesis of amine oxidase, catalase and the enzymes of the RuMP cycle is not under coordinate control.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00417184
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  • 3
    Electronic Resource
    Electronic Resource
    Microbodies in methanol-assimilating yeasts (1975)
    Springer
    Archives of microbiology 102 (1975), S. 41-44 
    Details
    ISSN: 1432-072X
    Keywords: Yeasts ; Methanol ; Microbodies
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Cells of 3 yeast species capable of assimilating methanol have been examined by electron microscopy. When grown on methanol as the sole source of carbon and energy they contained many microbodies. Cells grown on glucose or ethanol either did not contain such bodies at all, or only to a limited extent.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00428343
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  • 4
    Electronic Resource
    Electronic Resource
    A proton-translocating adenosine triphosphatase is associated with the peroxisomal membrane of yeasts (1987)
    Springer
    Archives of microbiology 147 (1987), S. 42-47 
    Details
    ISSN: 1432-072X
    Keywords: Hansenula polymorpha ; Yeast ; Peroxisomes ; Proton-translocating ATPase ; Cell fractionation ; Fluorescence quenching studies ; Cytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The association of an ATPase with the yeast peroxisomal membrane was established by both biochemical and cytochemical procedures. Peroxisomes were purified from protoplast homogenates of the methanol-grown yeast Hansenula polymorpha by differential and sucrose gradient centrifugation. Biochemical analysis revealed that ATPase activity was associated with the peroxisomal peak fractions which were identified on the basis of alcohol oxidase and catalase activity. The properties of this ATPase closely resembled those of the mitochondrial ATPase of this yeast. The enzyme was Mg2+-dependent, had a pH optimum of approximately 8.5 and was sensitive to N,N′-dicyclohexylcarbodiimide (DCCD), oligomycin and azide, but not to vanadate. A major difference was the apparent K m for ATP which was 4–6 mM for the peroxisomal ATPase compared to 0.6–0.9 mM for the mitochondrial enzyme. Cytochemical experiments indicated that the peroxisomal ATPase was associated with the membranes surrounding these organelles. After incubations with CeCl3 and ATP specific reaction products were localized on the peroxisomal membrane, both when unfixed isolated peroxisomes or formaldehyde-fixed protoplasts were used. This staining was strictly ATP-dependent; in controls performed i) in the absence of substrate, ii) in the presence of glycerol 2-phosphate instead of ATP, or iii) in the presence of DCCD, staining was invariably absent. Similar staining patterns were observed in subcellular fractions and protoplasts of Candida utilis and Trichosporon cutaneum X4, grown in the presence of ethanol/ethylamine or ethylamine, respectively.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00492903
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  • 5
    Electronic Resource
    Electronic Resource
    Proliferation and metabolic significance of peroxisomes in Candida boidinii during growth on d-alanine or oleic acid as the sole carbon source (1990)
    Springer
    Archives of microbiology 153 (1990), S. 485-489 
    Details
    ISSN: 1432-072X
    Keywords: Candida boidinii ; Yeast ; Peroxisomes ; β-Oxidation ; d-Amino acid oxidase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We have studied the induction of peroxisomes in the methylotrophic yeast Candida boidinii by d-alanine and oleic acid. The organism was able to utilize each of these compounds as the sole carbon source and grew with growth rates of μ=0.20 h-1 (on d-alanine) or μ=0.43 h-1 (on oleic acid). Growth was associated with the development of many peroxisomes in the cells. On d-alanine a cluster of tightly interwoven organelles was observed which made up 6.3% of the cytoplasmic volume and were characterized by the presence of d-amino acid oxidase and catalase. On oleic acid rounded to elongated peroxisomes were dominant which were scattered throughout the cytoplasm. These organelles contained increased levels of β-oxidation enzymes; their relative volume fraction amounted 12.8% of the cytoplasmic volume.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00248431
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  • 6
    Electronic Resource
    Electronic Resource
    Permeability properties of peroxisomal membranes from yeasts (1990)
    Springer
    Archives of microbiology 153 (1990), S. 490-495 
    Details
    ISSN: 1432-072X
    Keywords: Hansenula polymorpha ; Candida boidinii ; Peroxisome ; Peroxisomal membrane ; Permeability ; Membrane fusion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We have studied the permeability properties of intact peroxisomes and purified peroxisomal membranes from two methylotrophic yeasts. After incorporation of sucrose and dextran in proteoliposomes composed of asolectin and peroxisomal membranes isolated from the yeasts Hansenula polymorpha and Candida boidinii a selective leakage of sucrose occurred indicating that the peroxisomal membranes were permeable to small molecules. Since the permeability of yeast peroxisomal membranes in vitro may be due to the isolation procedure employed, the osmotic stability of peroxisomes was tested during incubations of intact protoplasts in hypotonic media. Mild osmotic swelling of the protoplasts also resulted in swelling of the peroxisomes present in these cells but not in a release of their matrix proteins. The latter was only observed when the integrity of the cells was disturbed due to disruption of the cell membrane during further lowering of the concentration of the osmotic stabilizer. Stability tests with purified peroxisomes indicated that this leak of matrix proteins was not associated with the permeability to sucrose. Various attempts to mimic the in vivo situation and generate a proton motive force across the peroxisomal membranes in order to influence the permeability properties failed. Two different proton pumps were used for this purpose namely bacteriorhodopsin (BR) and reaction center-light-harvesting complex I (RCLHI complex). After introduction of BR into the membrane of intact peroxisomes generation of a pH-gradient was not or barely detectable. Since this pump readily generated a pH-gradient in pure liposomes, these results strengthened the initial observations on the leakiness of the peroxisomal membrane fragments. Generation of a membrane potential (Δψ) was also not observed when RCLHI complex was introduced into vesicles of purified peroxisomal membranes. The significance of the observed permeability of isolated yeast peroxisomal membranes to small molecules with respect to current and future in vitro import studies is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00248432
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  • 7
    Electronic Resource
    Electronic Resource
    An electron microscope study of the yeast Pityrosporum ovale (1970)
    Springer
    Archives of microbiology 71 (1970), S. 123-131 
    Details
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Cells of Pityrosporum ovale were prepared for electron microscopy by different methods of fixation and embedding, all of them causing some degree of damage to the cells. Apart from the usual organelles seen in other yeast cells, a body was found which showed an electron-dense outer layer and an electron-light centre when stained with permanganate. The cell wall showed layers of different electron-density. Buds were formed at one pole only, leaving a collar on the mother cell.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00417738
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  • 8
    Electronic Resource
    Electronic Resource
    Characterization of peroxisomes in glucose-grown Hansenula polymorpha and their development after the transfer of cells into methanol-containing media (1979)
    Springer
    Archives of microbiology 120 (1979), S. 167-175 
    Details
    ISSN: 1432-072X
    Keywords: Peroxisome ; Biogenesis ; Yeast ; Hansenula polymorpha ; Cytochemical staining ; Methanol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Cells of Hansenula polymorpha growing exponentially on glucose generally contained a single peroxisome of small dimension, irregular in shape and located in close proximity to the cell wall. Crystalline inclusions in the peroxisomal matrix were not observed. Associations of the organelles with one or more strands of endoplasmic reticulum were evident. In stationary phase cells the size of the peroxisomes had increased considerably. They were more cubical in form and showed a partly or completely crystalline matrix. After the transfer of cells growing exponentially on glucose into media containing methanol, large peroxisomes with a partly crystalline matrix developed in the cells within 6 h. These organelles originated from the small peroxisomes in the glucose-grown cells. De novo synthesis of peroxisomes was not observed. Prolonged cultivation in the presence of methanol resulted in a gradual increase in the number of peroxisomes by means of separation of small peroxisomes from mature organelles. During growth of peroxisomes associations with the endoplasmic reticulum remained evident. The increase in volume density of peroxisomes in stationary phase cells grown on glucose and in methanol-grown cells was accompanied by the synthesis of the peroxisomal enzymes alcohol oxidase and catalase. Cytochemical staining techniques revealed that alcohol oxidase activity was only detected when the peroxisomes contained a crystalloid inclusion. Since in peroxisomes of an alcohol oxidase-negative mutant of Hansenula polymorpha crystalline inclusions were never detected, it is concluded that the development of crystalloids inside peroxisomes is due to the accumulation of alcohol oxidase in these organelles.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00409104
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  • 9
    Electronic Resource
    Electronic Resource
    Conjugation in the yeast Saccharomycopsis capsularis schiönning (1975)
    Springer
    Archives of microbiology 104 (1975), S. 263-269 
    Details
    ISSN: 1432-072X
    Keywords: Saccharomycopsis capsularis ; Conjugation ; Ascospores
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Cells of the yeast Saccharomycopsis capsularis fused in pairs after dissolving of part of the cross wall between them near the lateral wall. After nuclear migrations through the opening, the cross wall was closed again and the cells at both sides became asci. The wall of the ascospores developed from a prospore wall. Between the two unit membranes a very thin dark layer broadened to the dark layer of the wall and after that, the light inner layer developed. Immature spores in the strain studied had a ledge which disappeared during maturation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00447335
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  • 10
    Electronic Resource
    Electronic Resource
    Cytochemical localization of catalase activity in methanol-grown Hansenula polymorpha (1975)
    Springer
    Archives of microbiology 105 (1975), S. 261-267 
    Details
    ISSN: 1432-072X
    Keywords: Methanol ; Yeasts ; Microbodies ; Diaminobenzidine ; Catalase ; Methanol oxidase ; Hanseula polymorpha
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The localization of peroxidase activity in methanol-grown cells of the yeast Hansenula polymorpha has been studied by a method based on cytochemical staining with diaminobenzidine (DAB). The oxidation product of DAB occurred in microbodies, which characteristically develop during growth on methanol, and in the intracristate space of the mitochondria. The staining of microbodies was H2O2 dependent, appeared to be optimal at pH 10.5, diminished below pH 10 and was inhibited by 20 mM 3-amino 1,2,4 triazole (AT). In contrast to these observations, the reaction in the mitochondria was not H2O2 dependent and not notably affected by differences in pH in the range of 8.5 to 10.5. Microbodies and mitochondria were also stained when H2O2 was replaced by methanol. Appropriate control experiments indicated that in this case methanol oxidase generated the H2O2 for the peroxidative conversion of DAB by catalase. These results suggest that catalase is located in the microbodies of methanol-grown yeasts. A model for a possible physiological function of the microbodies during growth on methanol is put forward.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00447145
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